I dig it. Personally, one thing I would change, is I would add one piece of rock between the opening/valley on the left. It'll give more room for corals, and will add a contrast to the other spaciousness in the tank. Looks good though
Is the middle column leaning against the back?
Very respectable, I might have added more space from the sides to give it a more open look, also a bit concerned about cleaning.
Nicely done!
I think it's not bad already. Why not keep it like that???
I would lower your rocks some, it looks like there is very little vertical grow room for your corals. Also a little more mass like jflip said.
Looks good. The rock on the left idea would look good. Personally, I would stop the rocks a few inches lower, but it's not my tank. Great job!